Photon Focus MV1-D2080(IE) Series, User Manual, Page: 45 / 119

4.3 Reduction of Image Size
With Photonfocus cameras there are several possibilities to focus on the interesting parts of an
image, thus reducing the data rate and increasing the frame rate. The most commonly used
feature is Region of Interest (ROI).
4.3.1 Region of Interest (ROI)
Some applications do not need full image resolution (e.g. 2080 x 2080 pixels). By reducing the
image size to a certain region of interest (ROI), the frame rate can be drastically increased. A
region of interest can be almost any rectangular window and is specified by its position within
the full frame and its width (W) and height (H). Table 4.3 presents numerical examples of how
the frame rate can be increased by reducing the ROI.
Reductions in y-direction result in a higher frame rate. Reduction in x-direction
may result in a higher frame rate as the required data bandwidth is lowered.
The ROI width must be a multiple of 2.
✎
It is recommended to re-adjust the settings of the shading correction each time
a new region of interest is selected.
A frame rate calculator for calculating the maximum frame rate is available in
the support area of the Photonfocus website.
4.3.2 Interface restriction on maximum frame rate
The camera can be operated with settings that exceed the maximal available band width of
approx. 108 MB/s on the GigE interface. This will result in lost (dropped) images. The maximal
data rate for the GigE interface is:
maxFpsIf =
8
·
108
·
10
6
w · h · bpp
where w=width, h=height and bpp=bits per pixel (see also ).
Example:
w
=2080,
h
=2080,
bpp
=8 (8 bit mode):
maxFpsIf
= 24.96 fps. The camera indicates a
maximal frame rate of 34.8 fps. If 12 bits (Mono12Packed) is used instead then
maxFpsIf
is
reduced to 16.6 fps.
How can the maximal frame rate be decreased to comply with the formula shown before?
• In free-running mode ( TriggerMode =Off): if AcquisitionFrameRateMax is higher than maxFpsIf ,
then set AcquisitionFrameRateEnable to True and set AcquisitionFrameRate to maxFpsIf . If
maxFpsIf is lower than AcquisitionFrameRateMax , then AcquisitionFrameRateEnable can be set
to False to get the maximal frame rate.
• In external triggered mode ( TriggerMode =On) the applied trigger frequency must not
exceed
maxFpsIf
to avoid dropped images.
4.3 Reduction of Image Size 43